Newbie from PDX: Choosing Lightweight Front Hub Motor for Conversion

[LarryB]

Hello from Portland. I've been cycling for about 65 years and and still get that boyish grin every time I get on my bike.
I'm planning to electrify my bike, a 1980's Fuji Touring Series IV that I've converted to a city bike with a Shimano 8 speed Nexus rear hub.

I live in a fairly flat residential area of the city, but there is a 75' elevation gain on a common route. Most of my rides will be less than 10 miles (round trip), often with a backpack full of laptop and books or panniers full of groceries.

My priorities are reliability, quietness, and light weight. Don't need a lot of speed, and I am lightweight myself at 150 pounds.

I've settled on a small front hub motor, ~250 Watts, 24 or 36 Volt, ~10 AH battery.

I'm looking for advice/experience among these brands: LEEDS (e-bikerig.com), Hilltopper, Grin, and Cytronex (British). Your thoughts?

 

[indianajo]

Welcome to the site and electric propulsion.
I'm 68 and also use electricity to manage difficult terrain or winds. I enjoy the rubber necking I can do on a 10 mph bike compared with the attention required by a motor vehicle.
I've a front hub motor bike, but my motor was a 1000 W chinese brand, probably an LY. Plenty of power, PAS1 was a bit too fast for bad road conditions. I have several 100' hills with 15% grade to manage with 50 lb of supplies on the bike.
Be sure to install torque arms on the motor shaft to protect the front fork from fracture. I've been using SPAM can lids to make brackets to anchor the torque arms to the bike strut. But strips of steel cut out of old appliances are even stonger, just harder to work with tin snips. I use #10-32 machine screws, but 5 mm screws could work as well. Elastic stop nuts keep them from getting loose & falling off. The hardware is available in 25 or 50 packs from mcmaster.com
Have fun.

 

[LarryB]

Thanks for your quick reply!
What is PAS1? What did you use instead?
I have steel forks and frame, which is good for strength, but will look into torque arms as well. It sounds like I need one on each side of the axle? Are these commonly available from vendors? I'm pretty handy, but would prefer something purpose built. How are they anchored, can you post a photo or two? Thanks for the hardware link to Mcmaster.com!

 

[indianajo]

If you buy from a motor vendor like lunacycle (LA) ebikeling (wisconsen) or california-bat (I think, they are new) they have torque arms as an option that you buy with the power wheel. It all comes in the same box. Cheap display, LED display, thumb or twist throttle, shut-off brake handles or not, charger or not. If you canadian use grin tech of vancouver, if chinese use em3ev of Hong Kong.
I make my torque arms out of a sheet of steel (old bed frame), two 5/16" (8mm) holes drilled side by side, then grind out with a carbide burr or file out with round and triangle nicholsen files. My burr driver is 30 miles away so most recently I used the files, takes about 2.5 hours. Then #9 holes for the 10-32 screws of course.
PAS# is pedal assist, where you have a sensor on the crank and the motor helps you as you pedal and stops after you stop pedaling. 0 is off, 1 was about 11 mph on my purchase, I didn't use 2 or 3 yet. I'd have preferred PAS1 to be about 6 mph and 2 to be 11, but I haven't learned how to reprogram it.
So I use the twist throttle mostly. That bike never got over 13 miles from base due to battery quality issues, so I don't know if the motor is good or not yet. It is out at the summer camp 30 miles away.
Just bought a luna battery for 2.1X the price of the chinese ones, it works, got me 45 miles yesterday. Not enoght range to get out to the summer camp and back as I had hoped. ~50 miles out of 17.5 ah 48 v. My cargo bike I converted in town only has thumb throttle and no pedal sensor, and let me tell you, 4.5 hours of holding a thumb throttle is a real nuisance. The cargo bike has a rear direct drive hub installed, 1000 w, $179 last summer. I averaged 12 mph yesterday by contrast with the 8 mph I go usually pedal powered. Wind was no issue. I'm a sit up straight rider, so wind can extend my 3.5 hour 30 mile pedal powered commute to 5.7 hours if in my face. No more of that, I have electricity now, running as of yesterday.

 

[harryS]

I've bought a couple of geared motors (three) from this vendor.
(Link Removed - No Longer Exists)

The first two worked great. Just a simple LED display and three level pedal assist. On 36V, 20 mph was possible. For the third one, I went fancy and got the LCD display, but the controller was very sad. It went to 18 mph as soon as I spun the pedals on any of the five assist levels. Not rideable. I had to use another controller. So I would look at the LED model if you look at the above vendor.

You still need a battery though. A 36V11AH battery will take me well over 50 miles on the above motors using pedal asist at 13 mph. Some people think that's too slow. Probably could go 14 mph and still get 40 miles.

I did rear conversions though. Here are two with the above hub. My old Trek 800 with a $280 battery. The second is a Schwinn SC2000 (found in dumpster) with battery in the bag.

I have done one front conversion on an aluminum fork with two torque arms. I marked the axle nuts with a sharpie, so it's part of my pre-ride inspection to see if they moved.

 

[Ravi Kempaiah]

Hello from Portland. I've been cycling for about 65 years and and still get that boyish grin every time I get on my bike.
I'm planning to electrify my bike, a 1980's Fuji Touring Series IV that I've converted to a city bike with a Shimano 8 speed Nexus rear hub.

I live in a fairly flat residential area of the city, but there is a 75' elevation gain on a common route. Most of my rides will be less than 10 miles (round trip), often with a backpack full of laptop and books or panniers full of groceries.

My priorities are reliability, quietness, and light weight. Don't need a lot of speed, and I am lightweight myself at 150 pounds.

I've settled on a small front hub motor, ~250 Watts, 24 or 36 Volt, ~10 AH battery.

I'm looking for advice/experience among these brands: LEEDS (e-bikerig.com), Hilltopper, Grin, and Cytronex (British). Your thoughts?

@JRA lives close to you and has a front hub conversion.

He could help you with tips and suggestions.

 

[JRA]

I would recommend working with Grin. They are the most knowledgeable resource for hub motor systems that I know of. They are really into the G series motors and although I use their All Axle motor if I was in your situation I would go with the G311 geared front hub motor kit that they would be happy to advise you on the parts necessary to get your bike set up for your particular needs. Plus you could road trip to Vancouver to get the parts and if you feel uncomfortable with your ability to perform the conversion pretty sure that with a heads up they would be able to do so for you. .